Currently, in the field of on-vehicle applications, there are mainly two implementations for antenna design of a broadcast receiving application (for example, AM/FM, DAB/DMB, and TV): one is a solution to integrate an antenna into a rear windshield to share a defogger wire therewith, and the other is a solution to integrate the antenna into a shark fin. Antenna applications use low frequency bands, and a relatively large space is required to implement the functions and performance of the antenna. Therefore, the former solution is more aesthetic than the latter. However, in development stages, antennas need to be separately developed for different models, resulting in long development periods and relatively high costs. The latter solution has simple development. The same design may be used as a modular product and can be applied to different models without any change. Therefore, the latter solution is significantly advantageous in reducing development investments and batch production costs. However, there are challenges in performance and implementation processes due to space limitations for aesthetic reasons. A current shark fin usually comprises a broadcast receiving antenna and a satellite navigation receiving antenna. In some shark fins, a cellular antenna is further added. Two antennas are required for 4G cellular communication. As new functions are further added, the space for each antenna in a shark fin is further reduced, and interference between the antennas further needs to be minimized.
In a current well-known shark fin, a broadcast receiving antenna mainly uses an axial-mode helical antenna or a magnetic helical antenna, a metal umbrella antenna, a PCB antenna, among other antenna patterns. The axial-mode helical antenna or magnetic helical antenna occupies the upper space of the entire shark fin and thus greatly affecting the layout of other antennas. The metal umbrella antenna needs to be supported, for example, by a substrate and equipped with an induction coil to improve the performance, resulting in relatively complex process implementation and a large occupied space. The PCB antenna has simple implementation but undesirable performance.